1. Field of the Invention
The present invention relates to automotive seat slide devices of a type which includes a walk-in mechanism which permits a forward movement of the seat when a seatback is inclined forward, a seatbelt retractor which permits feeding and retracting of a seatbelt associated with the seat and a check mechanism which checks the feeding of the seatbelt when the seat is subjected to a certain shock due to a vehicle collision or the like.
2. Description of the Prior Art
Hitherto, there have been proposed various seat slide devices particularly in the field of passenger cars. Usually, the seat slide device comprises a pair of stationary rails securedly mounted on a vehicle floor, and a pair of movable rails mounting thereon a seat and slidably engaged with the stationary rails. Thus, upon requirement of the seat position adjustment, the movable rails are moved together with the seat on and along the stationary rails to a desired position.
Some of these seat slide devices are of a type which has a so-called "inertia locking type seatbelt retractor" fixed to one of the movable rails. In fact, the seat slide devices of this type are employed in a passive seat belt system which automatically fits the passenger with the seatbelt when the door is closed.
One of the seat slide devices of the above-mentioned type is shown in Japanese Utility Model First Provisional Publication No. 63-58050.
That is, in the device of the publication, under a normal locked condition of the seat slide device wherein the movable rails are locked to the stationary rails, the inertia locking seatbelt retractor secured to the movable rail is in OFF state wherein feeding and retracting of the seatbelt are available in response to the forward and rearward inclination of the upper part of a passenger on the seat. While, when, due to a vehicle collision or the like, the retractor is applied with a certain shock, an inertia sensor associated with the retractor senses the shock and instantly causes the retractor to lock the seatbelt and thus restrain the passenger.
In order to move the seat from the locked position to a new desired position, an operation handle is manipulated to cancel the locked condition of the movable rails and then, with the operation handle kept manipulated, the seat is pushed forward or rearward to the new desired position. However, for carrying out this movement, it is necessary to disable the inertia sensor from sensing a shock. That is, if the inertia sensor becomes operated by a shock produced during, for instance, a forward movement of the seat, the passenger, viz., belt wearer, is uncomfortably pressed by the locked seatbelt against the seatback.
In the seat slide device of the publication, there is thus employed an electric system which comprises a switch which turns ON when the operation handle is manipulated for unlocking the movable rails, and an electric actuator which is connected to the switch, so that upon the switch turning on, the actuator makes the inertia sensor inoperative.
However, the seat slide device of the publication becomes to have a drawback when it is equipped with a walk-in mechanism. That is, in this case, a so-called transmitting mechanism is usually employed for converting the forwardly inclining movement of the seatback to the lock cancelling movement of the operation handle. However, this means that during the time for which the seatback is kept inclined forward, the switch is kept on causing the wasteful energization of the electric actuator. In fact, it often occurs that the passenger leaves the vehicle with the seatback kept inclined forward. This causes an undesirable over-discharging of the battery mounted on the vehicle.